How to test an EBM PAPST R2E motor?

[badgered1]

Hi everybody.
I have a smoke extraction fan on my pellet boiler which is controlled at different speeds during the ignition and run phases.

Its not running fast enough.
Now I don't know if its the motor or the speed controlling from the board at fault.

It has a pair of wires, from the board at constant 240v ac, heavier gauge. Plus three wires fine gauge which have varying outputs from the board of 18-24v ac.

If I disconnect the three way speed controlling connector the motor spins up to its correct speed. But the pellet boiler puts itself into fault mode and shuts down.

Is there a way to test the windings if I disconnect the connectors and measure the resistances?

One minor point, the motor had to be manually spun to start with this season, but starts itself now.
So I don't think its the capacitor, or am I wrong?

Thanks in advance for any clues.

[capt bullshot]

I'd guess the fan motor is OK as it runs as desired while the control wires are disconnected.
I'd suspect some digital (PWM) signal at the three-pin connector,
one from the board to the motor to set the speed, and another one from motor to board providing feedback. Third wire would be common. So you'd need an oscilloscope to check these signals for correct operation.

[badgered1]

Great thanks capt.

Yes the motor should be good for tens of thousands of hours and it will run flat out.


Unfortunately I'm not advanced enough for an oscilliscope... I'll have to ask Santa


But labelled on the board there is the three connectors as R B and N. (Its Italian make)

[badgered1]

Just posting a pic of the board, the is a bit of discolouration around a small chip.

[Armadillo]

That is a single phase capacitor start AC motor. You can measure the ohms of the main coil and the run coil. The capacitor should be around 1uF.

I suspect the 3 wires is from the HALL sensor but it should be 5V, Gnd, and Pulse signal, if it is HALL sensor.

The best is to get the single lines from the manufacturer of the machine. Otherwise, you should visual the sensor the wires lead to and identify the sensor.

[capt bullshot]

Just posting a pic of the board, the is a bit of discolouration around a small chip.

It's IC1, isn't it? Look at the nice blow hole, this thing clearly had let the smoke go.
I guess, it's best to replace that board, you could try to identify and replace the chip first, but it may blow again.

[badgered1]

Yes Capt its IC1. I think that might be the culprit.

Would a stuck motor caused that overheat I wonder.

[badgered1]

I'll have a go at testing the motor as thanks.

[badgered1]

Its a 93C46WP chip.

If I got one, would simply replacing it work? As in, it wouldn't need reprogramming etc.

[jmelson]

Its a 93C46WP chip.

If I got one, would simply replacing it work? As in, it wouldn't need reprogramming etc.

Nope, it is the EEPROM that holds the code for the micro, so it WOULD have to be programmed with the correct code for this board.

Jon

[capt bullshot]

Its a 93C46WP chip.

If I got one, would simply replacing it work? As in, it wouldn't need reprogramming etc.

For sure it would hold some data. If these have to be restored depends on how the manufactured designed the software. So I can't tell.
Anyway, your typical EEPROM doesn't have any connection to the (evil) outside except for the power supply, so to me it's rather surprising an EEPROM failed that way. I'd guess there's another failure that caused the EEPROM to release the smoke, maybe too high a supply voltage.

[Armadillo]

128 bytes over microwire serial bus? Most Unlikely.

He did not describe any display or startup problem, just the problem with the motor speed.

If ever the EEPROM is defective, probably some default settings example the exhaust fan speed at startup, probably.

Its a 93C46WP chip.

If I got one, would simply replacing it work? As in, it wouldn't need reprogramming etc.

Nope, it is the EEPROM that holds the code for the micro, so it WOULD have to be programmed with the correct code for this board.

Jon